[unreadable] The objective of this study is to combine the efforts of MR scientists and radiation oncologists at the University of California at San Francisco (UCSF) with engineers at General Electric Medical Systems (GEMS) in developing data acquisition, reconstruction and post-processing capabilities for integrating Magnetic Resonance Spectroscopic Imaging (MRSI) data into radiation treatment planning for cancer patients. The motivation for this translational research has come from recent improvements in radiation treatment delivery systems that are able to conform dose very precisely to irregularly shaped 3-D targets. MRSI research studies at UCSF have shown that the spatial extent of the metabolic abnormality is often significantly different from the lesion observed with conventional MR imaging and that this is likely to have a major impact upon target definition. As a result of the studies at UCSF and supporting data from other institutions, the Radiation Therapy Oncology Group (RTOG) has proposed a multi-center clinical trial of the value of MRSI in targeting gliomas. A prerequisite for performing this study is the translation of the technology into robust tools that are available on clinical MR scanners and that integrate MRSI into the treatment planning process in a timely and efficient manner. This requires active participation from the manufacturer of the MR scanner. The scientists and clinicians at UCSF have already demonstrated the ability to form a partnership with GEMS in developing MRSI packages. This experience will now be directed towards a developing a prototype package for integrating MRSI into radiation treatment planning of brain tumors. Although this R21 project will focus on a single tumor site, the package will be constructed in a modular fashion so that the tools developed can be adapted to other types of tumors and used in conjunction with multiple imaging and treatment platforms. [unreadable] [unreadable] [unreadable]